1. Field
The following description relates to methods and apparatuses for generating a medical image and to, for example, methods and apparatus of generating a positron emission tomography (PET) image by using a linear gamma ray source.
2. Description of Related Art
A medical image device is used to diagnose a patient by obtaining information about the patient via an image of the functional processes that are taking place inside the human body. Methods of capturing a medical image have actively been developed and are currently used in hospitals. Such methods are largely divided into methods of obtaining an anatomical image and methods of obtaining a physiological image. Examples of imaging technologies that provide a detailed, high resolution anatomical image of the human body include magnetic resonance imaging (MRI) and computed tomography (CT). In such an imaging technology, a 2-dimensional (2D) image of a cross-section of the human body or a 3D image of the human body or a part thereof is generated so as to show accurate locations and shapes of organs in the human body. The 3D image may be obtained by using several 2D high-resolution images. An example of technology for acquiring a physiological image includes positron emission tomography (PET). PET can be used to diagnose a metabolic disorder by obtaining an image of the metabolic processes that are take place inside the human body.
PET is an imaging technology in which special radioactive tracers that emit positrons are generated in the forms of components participating in the metabolic processes of the human body. The tracers are injected into the human body via an intravenous injection or inhalation, and the locations of the tracers are obtained by using an external device (a scanner) that detects two gamma rays of 511 eV emitted in opposite directions to each other when the positrons emitted from the tracers and electrons combine with each other. Both the pattern of distribution of the gamma rays and a change in the distribution pattern with respect to time may be observed.
In this regard, physiological phenomena that continue to occur inside the body during a process of detecting a gamma ray, a geometrical structure of a detector, spatial restrictions due to the shape and arrangement of detection elements in the detector, and the like, may adversely affect a spatial resolution of the PET, and may further influence the ability of a user to read and interpret a patient's image or deteriorate the disease diagnostic capability of the imaging device. Among such spatial resolution deterioration factors, it is in particular impossible to control the continued occurrence of physiological phenomena inside the body. Further, spatial restrictions may cause a design issue that is difficult to overcome with respect to the structure of the detector.